Sensing system and sensing method using the same

Abstract

The present invention relates to a sensing system and a sensing method using the same. The sensing system includes at least one tested unit and an optical fiber measuring unit. The tested unit includes a container, a strain arm and a float. The container can be filled with a fluid, and the strain arm is connected with the float and combined with a measuring portion of the optical fiber measuring unit. When the container is disposed on a body of interest, the surface inclination or settlement of the body of interest would cause changes of buoyant force on the floating element and induce bending deformation of the strain arm. Accordingly, the surface deformation of the body of interest can be determined by detecting the bending deformation of the strain arm using the measuring portion combined with the strain arm.

What is claimed is: 
     
       1. A sensing system, including:
 at least one tested unit comprising a container, a strain arm, and a float, wherein an accommodating space is defined in the container for accommodating a fluid, the strain arm has a fixed end and a free end, wherein the fixed end of the strain arm connects to a side wall of the container, and the free end of the strain arm overhangs in the accommodating space and connects to the float, the float shifts by changes of buoyant force and induce a bending deformation of the strain arm; and 
 an optical fiber measuring unit having at least one measuring portion, wherein the measuring portion combines with the strain arm and extends between the fixed end and the free end for detecting the bending deformation of the strain arm. 
 
     
     
       2. The sensing system as claimed in  claim 1 , wherein a grating is formed at the measuring portion, and the bending deformation of the strain arm induces changes of grid line spacing of the grating. 
     
     
       3. The sensing system as claimed in  claim 1 , wherein the sensing system detects surface inclination or settlement of a body of interest and physical parameters relate to surface inclination or settlement of the body of interest is determined by detecting the bending deformation of the strain arm using the measuring portion. 
     
     
       4. The sensing system as claimed in  claim 1 , wherein the tested unit further comprises an adjustable platform for disposing the container thereon and adjusting a horizontality of the body of interest when the container is disposed on the body of interest. 
     
     
       5. The sensing system as claimed in  claim 4 , wherein the adjustable platform further comprises a defining structure for defining a disposing region, so that the container is fixed at the disposing region when the container is disposed on the adjustable platform. 
     
     
       6. The sensing system as claimed in  claim 1 , wherein a horizontal reference line is marked on the container, the strain arm remains horizontally unbent when the liquid level of the fluid aligns to the horizontal reference line. 
     
     
       7. The sensing system as claimed in  claim 1 , wherein the optical fiber measuring unit comprises an optical fiber, an optical module, and a signal processing module, wherein the measuring portion is disposed on a portion of the optical fiber where corresponds to the strain arm; the optical module is utilized to transmit an input signal to the optical fiber, and the measuring portion generates an output signal which is transmitted to the optical module after the input signal is processed, and the signal processing module is utilized to obtain a physical parameter by analyzing the output signal. 
     
     
       8. The sensing system as claimed in  claim 1 , wherein the buoyant force applied to the float changes when the container inclines and the deformation level of the strain arm relates to the incline angle of the container. 
     
     
       9. The sensing system as claimed in  claim 8 , wherein the tested unit further comprises a water vapor adsorption plate for cap sealing the container and adsorbing saturating amount of water. 
     
     
       10. The sensing system as claimed in  claim 1 , wherein the tested unit includes a plurality of the tested unit; and at least one connecting tube for connecting the accommodating spaces of the containers, so that the liquid levels of the fluid in the accommodating spaces maintain at a same level based on connected pipes principle. 
     
     
       11. The sensing system as claimed in  claim 10 , wherein the buoyant force applied to the float changes when the container shifts relatively in a vertical direction, and a level of the bending deformation of the strain arm relates to a relevant displacement between the containers. 
     
     
       12. A sensing method using the sensing system as claimed in  claim 1 , comprising the steps of:
 disposing the container on the body of interest, and the fluid is accommodated in the accommodating space of the container; 
 driving the optical fiber measuring unit to provide an input signal to the measuring portion, and the measuring portion generates an output signal after the input signal is processed, when the surface of the body of interest occurs inclination or settlement, the buoyant force applied to the float changes, and changes the output signal; and 
 analyzing the output signal to obtain the physical parameters relevant to inclination or settlement of the body of interest. 
 
     
     
       13. The sensing method as claimed in  claim 12 , wherein the container is horizontally disposed on the body of interest, and the buoyant force provided by the fluid equals to the weight of the float, so that the strain arm exhibit a horizontally unbent initial state, and a measured value corresponds to the initial state serves as an initial point for evaluating whether inclination or settlement of the body of interest occurs.